Flameshot for screenshot taking and annotation. Goodvibes for online radio listening. Workrave and Rescuetime to limit my screen time. CopyQ to manage my clipboard. Xfce to provide me with a well-functioning desktop.
Not necessarily alternative but I saw that for example Google seems to be trying to reinvent the wheel with emailing and calendar, introducing features like "Snooze", "Reminders", or "Goals". I am wondering how useful or widely used this features are or whether traditional approaches to email and calendar are just fine and sufficient.